1. Field of the Invention
This invention relates to an improved charge transfer sequencing system for a solid state imaging device and, more particularly, to an improved system of transferring still image defining data from a solid state sensor in an electronic imaging camera.
2. Background of the Invention
High resolution solid state image sensors such as charge coupled devices (CCD), charge injection device detectors (CID) and so forth are finding increasing use as imaging elements for electronic cameras. Such high resolution image sensors produce a large number of pixels for each horizontal line scan of their output. The light sensing arrays may comprise over 1000 discrete light sensing areas or pixels arranged in as many as 500 lines or rows. Recently, electronic imaging cameras of the type that can be operated in either a moving picture mode of operation or a still picture mode of operation have been proposed. Such cameras require a high resolution image sensor which when operated in the still image mode provide the requisite resolution to achieve a quality still image. The clocking or transfer of image data from the light sensing device presents different problems depending upon the mode of operation selected for use of the camera. For example, in the moving picture video mode of operation, conventional field and frame transfer rates of 1/60th and 1/30th of a second, respectively, must be maintained and the image data must be transferred at times compatible with these rates. However, to achieve a high quality moving video image it is not necessary that all the image data sensed by the high resolution array be ultimately transferred from the array. By contrast, however, in order to provide a high quality still image it is necessary that substantially all of the image data be transferred from the light sensing array albeit not necessarily at rates compatible with the standard field and frame rates.
Therefore, it is a primary object of this invention to provide an improved means for transferring still image data from a light sensing array in an electronic image camera in a manner whereby the still image data for each succeeding line of pixels is transferred at rates substantially less than standard video field and frame rates while being simultaneously dessimated.
Other objects of the invention will be in part obvious and will in part appear hereinafter. The invention accordingly comprises a circuit and system possessing the construction, combination of elements and arrangement of parts which are exemplified in the following detailed disclosure.